The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c
2
by precisely measuring the endpoint region of the ...tritium
β
-decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Liu, T.-N., Gu, L.-M., Xu, C.-L. and Dong, S.-T. 2014. Responses of group and individual leaf photosynthetic characteristics of two summer maize (Zea mays L.) to leaf removal under high plant ...density. Can. J. Plant Sci. 94: 1449–1459. The present experiment was conducted during the growing seasons of 2012 and 2013 using two summer maize (Zea mays L.) cultivars, Zhengdan958 (a compact cultivar) and Jinhai5 (a semi-compact cultivar) grown at a plant density of 105 000 plants ha −1 , to evaluate the influence of leaf removal on canopy apparent photosynthesis (CAP), individual leaf photosynthetic characteristics and grain yield. Plants were subjected to the removal of two (S1), four (S2) or six leaves (S3) from the top of the plant 3 d after anthesis (DAA), with no leaf removal as control (S0). The results of 2 yr indicated that with increased intensity of leaf removal, the transmission of light to lower strata of the canopy increased. With the removal of two leaves (S1), CAP increased and longer durations of CAP and green leaf are index were maintained during grain filling, whereas CAP in S2 and S3 treatments was inhibited and drastically declined. Generally, leaf removal appeared to stimulate an increase in the net photosynthetic rate (P N ), stomatal conductance (g s ) and chlorophyll content of the remaining ear leaves in S2 and S3 treatments prior to 26 DAA. Nevertheless, thereafter, plants in the S1 treatment had an advantage in terms of individual photosynthetic capacity. These results indicate that excising two leaves made plants more tolerant of high plant density due to enhanced photosynthetic capacity in ear leaves as well as a more efficient canopy structure, resulting in a better coordination of groups and individuals, and finally achieved significantly higher grain yield. In addition, relative to Zhengdan958, the effects of leaf removal on Jinhai5 were more apparent.
Fertilizer use remains very low in most of Africa despite widespread agreement that much higher use rates are required for sustained agricultural productivity growth. This study uses longitudinal ...farm survey data to estimate maize yield response functions in a relatively high-potential zone of Zambia to determine the profitability of fertilizer use under a range of small-farm conditions found within this zone. The theoretical framework used in this study incorporates agronomic principles of the crop growth process. We generalize the asymmetric production models and define a concept of yield scaling factors. The model distinguishes different roles of inputs and non-input factors in crop production. We estimate the effects of conventional production inputs as well as of household characteristics and government programs on maize yield. The results indicate that recommended fertilizer application rates in the two specific years were often unprofitable, given observed price conditions and the yield response to fertilizer. However, there was substantial variability in yield response to fertilizer based upon the rate of application, the timeliness of fertilizer availability, the use of animal draught power during land preparation, and whether the household incurred the death of an adult member in the past three years. These modifying factors, as well as variations in input and output prices due to proximity to roads and markets, substantially affected the profitability of fertilizer use on maize.
The US Food and Drug Administration's Sentinel system has developed the capability to conduct active safety surveillance of marketed medical products in a large network of electronic healthcare ...databases. We assessed the extent to which the newly developed, semiautomated Sentinel Propensity Score Matching (PSM) tool could produce the same results as a customized protocol‐driven assessment, which found an adjusted hazard ratio (HR) of 3.04 (95% confidence interval CI, 2.81–3.27) comparing angioedema in patients initiating angiotensin‐converting enzyme (ACE) inhibitors vs. beta‐blockers. Using data from 13 Data Partners between 1 January 2008, and 30 September 2013, the PSM tool identified 2,211,215 eligible ACE inhibitor and 1,673,682 eligible beta‐blocker initiators. The tool produced an HR of 3.14 (95% CI, 2.86–3.44). This comparison provides initial evidence that Sentinel analytic tools can produce findings similar to those produced by a highly customized protocol‐driven assessment.
Clinical documentation is central to patient care. The success of electronic health record system adoption may depend on how well such systems support clinical documentation. A major goal of ...integrating clinical documentation into electronic heath record systems is to generate reusable data. As a result, there has been an emphasis on deploying computer-based documentation systems that prioritize direct structured documentation. Research has demonstrated that healthcare providers value different factors when writing clinical notes, such as narrative expressivity, amenability to the existing workflow, and usability. The authors explore the tension between expressivity and structured clinical documentation, review methods for obtaining reusable data from clinical notes, and recommend that healthcare providers be able to choose how to document patient care based on workflow and note content needs. When reusable data are needed from notes, providers can use structured documentation or rely on post-hoc text processing to produce structured data, as appropriate.
In the present paper the effects of explosion hardening on the microstructure and the mechanical properties as well as the lifetime of Hadfield steel (high manganese steel) crossing have been ...studied. The optimum explosion hardening technology of the high manganese steel crossing was proposed. That is twice explosion by using cyclonite explosive in thickness of 3 mm. The new technology emphasises the formation of a 25 mm deep hardened layer with surface hardness of 370 HB. Upon the explosion impact, the deformation mechanism of the material is found to follow in situ plastic deformation. The explosion hardening mechanisms of the high manganese steel crossing are dislocation and nanoscale deformation twin hardenings in the surface layer which is subjected to large deformation, and dislocation hardening in the subsurface layer which is subjected to small deformation. The explosion hardening enhances the mechanical properties of the material, included the deformation resistance, wear resistance and fatigue resistance, therefore, the lifetime of the high manganese steel crossing can be increased by ∼35% through the explosion hardening treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The thickness of pavement structural layer is one of the key indicators of pavement quality detection, which has a great impact on the normal use of the pavement. Among the algorithms that ...calculating this indicator, particle swarm optimization algorithm has low inversion accuracy while genetic algorithm has low inversion efficiency. This thesis put forward a hybrid inversion analysis method based on particle swarm optimization and genetic algorithm. By taking the advantages of the above two algorithms and combining the characteristics of selection, crossover, mutation of genetic algorithm and fast convergence of particle swarm optimization, this method could improve the accuracy of inversion under the condition of ensuring the computational efficiency. The analysis of the inversion results of theoretical model and field core sampling results verified the accuracy of inversion results, and the feasibility and effectiveness of the proposed algorithm were proved.
PDF
